tell somebody/something apart phrasal verb (see also tell)
if you can tell two people or things apart, you can see the difference between them, so that you do not confuse them Synonym : distinguish:
It’s almost impossible to tell the twins apart.

[TahlilGaran] Dictionary of Contemporary English ▲

tell apart
tell (someone/something) apart
to be able to see the difference between one person or thing and another.
One guy's a Democrat and the other's a Republican, but it wasn't always easy to tell them apart.

The twins are no longer as hard to tell apart as when they were little babies.

She held out two flowers, but I couldn't tell which was which.

[TahlilGaran] English Idioms Dictionary ▲

tell something apart
tell (someone/something) apart
to be able to see the difference between one person or thing and another.
One guy's a Democrat and the other's a Republican, but it wasn't always easy to tell them apart.

The twins are no longer as hard to tell apart as when they were little babies.

She held out two flowers, but I couldn't tell which was which.

[TahlilGaran] English Idioms Dictionary ▲

tell apart
• tell apart (two things or people)
to distinguish between two things or people
It is hard to tell the two sisters apart.

[TahlilGaran] English Idioms Dictionary ▲

tell apart
v. phr. To see the difference between; know each of.
The teacher could not tell the twins apart.

[TahlilGaran] English Idioms Dictionary ▲